In Mission 13 of Sniper: Ghost Warrior (the one where you're playing as the spotter), after the target has been assassinated and you're escaping the area, you come to a bridge with a patrol on the other side and are told to sneak into the river. However, that involves crossing a couple of metres of exposed ground to the left of the bridge, and when I do that, the enemies instantly spot me (threat meter goes immediately to full red), open fire and kill me in a couple of seconds. I've tried crawling as well as running, but no luck.
How am I supposed to get past that section? Is it a glitch of some sort, or is there a trick to it? So far my workaround has been to "snipe" as many of the enemies as possible from behind cover with the silenced pistol, then run to the river and hope the remaining ones don't kill me. But I doubt that's how it's supposed to be done. Any ideas?
I'm playing on the PC and on medium difficulty, in case that matters.